<template>
  <div>
    <a-menu mode="inline" :openKeys="openKeys" @openChange="onOpenChange" style="width: 256px">
      <a-sub-menu key="sub1">
        <span slot="title"><a-icon type="mail" /><span>Navigation One</span></span>
        <a-menu-item key="1">Option 1</a-menu-item>
        <a-menu-item key="2">Option 2</a-menu-item>
        <a-menu-item key="3">Option 3</a-menu-item>
        <a-menu-item key="4">Option 4</a-menu-item>
      </a-sub-menu>
      <a-sub-menu key="sub2">
        <span slot="title"><a-icon type="appstore" /><span>Navigation Two</span></span>
        <a-menu-item key="5">Option 5</a-menu-item>
        <a-menu-item key="6">Option 6</a-menu-item>
        <a-sub-menu key="sub3" title="Submenu">
          <a-menu-item key="7">Option 7</a-menu-item>
          <a-menu-item key="8">Option 8</a-menu-item>
        </a-sub-menu>
      </a-sub-menu>
      <a-sub-menu key="sub4">
        <span slot="title"><a-icon type="setting" /><span>Navigation Three</span></span>
        <a-menu-item key="9">Option 9</a-menu-item>
        <a-menu-item key="10">Option 10</a-menu-item>
        <a-menu-item key="11">Option 11</a-menu-item>
        <a-menu-item key="12">Option 12</a-menu-item>
      </a-sub-menu>
    </a-menu>
  </div>
</template>
<script>
  export default {
    data() {
      return {
        rootSubmenuKeys: ['sub1', 'sub2', 'sub4'],
        openKeys: ['sub1'],
      };
    },
    methods: {
      onOpenChange(openKeys) {
        //如果打开菜单不是当
        const latestOpenKey = openKeys.find(key => this.openKeys.indexOf(key) === -1);
        console.log(`latestOpenKey=${latestOpenKey}`)
        if (this.rootSubmenuKeys.indexOf(latestOpenKey) === -1) {
          this.openKeys = openKeys;
        } else {
          this.openKeys = latestOpenKey ? [latestOpenKey] : [];
        }
      },
    },
  };
</script>
